JsonCircularReference class: Difference between revisions

Latest revision as of 00:44, 13 May 2015

JsonCircularReference exceptions are thrown by the Stringify function in the Json class if the Json object leads to a circular reference.

The JsonCircularReference class, like the Json class, is available as of Model 204 7.6.

The JsonCircularReference methods

The following are the available JsonCircularReference class methods.

Method	Description
New	Create a new JsonCircularReference object

The methods in the class are described in the subsections that follow. In addition:

Notation conventions for methods has information about the conventions followed.
JsonCircularReference methods syntax is a single page that contains the syntax diagrams of all the methods in the class.

New constructor

Create a new JsonCircularReference object (JsonCircularReference class)

This Constructor generates an instance of a JsonCircularReference exception. The New method format is as follows:

Syntax

%jsonCircularReference = [%(JsonCircularReference):]New

Syntax terms

%JsonCircularReference	A reference to an instance of a `JsonCircularReference` object.
`[%(JsonCircularReference):]`	The class name in parentheses denotes a `Constructor`.

Usage notes

The following example catches a circular reference exception and prints the string where the circular reference occurs.

b %jsonCircRefError is object JsonCircularReference %jsa is object json %jsb is object json %jsc is object json %jsa = array('a') %jsb = array('b') %jsc = array('c') %jsa:add(%jsb) %jsb:add(%jsc) %jsc:add(%jsa) try print %jsa:stringify catch JsonCircularReference to %jsonCircRefError print 'Caught Json Circular Reference Error' print %jsa:tostring end try end

Running this example results in:

Caught Json Circular Reference Error ["a",["b",["c",[Circular]]]]

@@ Line 1: / Line 1: @@
 <!-- JsonCircularReference class -->
-JsonCircularReference exceptions are thrown by the Stringify function in the Json class if the Json object leads to a circular reference.
+__NOTOC__
+<var>JsonCircularReference</var> [[Exceptions|exceptions]] are thrown by the <var>[[Stringify (Json function)|Stringify]]</var> function in the <var>[[Json class|Json]]</var> class if the <var>Json</var> object leads to a [[Json class#Circular references|circular reference]].
-To produce a <var>JsonCircularReference</var> exception for yourself, you typically use a <var class="product">SOUL</var> <var>[[Exceptions#Throwing exceptions|Throw]]</var> statement with a <var>JsonCircularReference</var> <var>[[New_(JsonCircularReference_constructor)|New]]</var> constructor.  This statement must be issued from within a method, and it can only be caught by the code that calls the method.  For example, the following statement throws a <var>JsonCircularReference</var> exception:
+The <var>JsonCircularReference</var> class, like the <var>Json</var> class, is available as of <var class="product">Model 204</var> 7.6.
-<p class="code">throw %(JsonCircularReference):new
-</p>
-Remember that you catch an exception with the <var>[[Exceptions#Try and Catch|Catch]]</var> statement; if an exception condition occurs outside a <var>Catch</var> for it, the request is canceled.
-The <var>JsonParseError</var> class, like the Json class is available as of <var class="product">Model 204</var> 7.6.
 ==The JsonCircularReference methods==
@@ Line 18: / Line 13: @@
 <li>[[JsonCircularReference methods syntax]] is a single page that contains the syntax diagrams of all the methods in the class. </li>
 </ul>
 ==New constructor==
@@ Line 29: / Line 23: @@
 ====Syntax terms====
-<table class="syntaxTable">
+<table>
 <tr><th>%JsonCircularReference </th>
 <td>A reference to an instance of a <var>JsonCircularReference</var> object.
 </td></tr>
-<tr><th><var>[%(JsonCircularReference):]</var></th><td>The class name in parentheses denotes a <var>[[Notation conventions for methods#Constructors|Constructor]]</var>. See [[#Usage notes|Usage notes]], below, for more information about invoking a <var>JsonCircularReference</var> <var>Constructor</var>.</td></tr>
+<tr><th><var>[%(JsonCircularReference):]</var></th>
+<td>The class name in parentheses denotes a <var>[[Notation conventions for methods#Constructors|Constructor]]</var>.</td></tr>
 </table>
 ===Usage notes===
-<ul>
+<p>
-<li>As described in [[Object variables#Using New or other Constructors|Using New or other Constructors]], <var>New</var> can be invoked with no object, with an explicit class name, or with an object variable in the class, even if that object is <var>Null</var>:
+The following example catches a circular reference exception and prints the string where the circular reference occurs.
-<p class="code">%jcircref = new
+</p>
+<p class="code">b
-%jcircref = %(JsonCircularReference):new
+%jsonCircRefError    is object JsonCircularReference
+%jsa is object json
-%jcircref = %jcircref:new
+%jsb is object json
+%jsc is object json
+%jsa = array('a')
+%jsb = array('b')
+%jsc = array('c')
+%jsa:add(%jsb)
+%jsb:add(%jsc)
+%jsc:add(%jsa)
+try
+print %jsa:stringify
+   catch JsonCircularReference to %jsonCircRefError
+     print 'Caught Json Circular Reference Error'
+     print %jsa:tostring
+end try
+end
 </p>
-</ul>
+Running this example results in:
+<p class="output">Caught Json Circular Reference Error
+["a",["b",["c",[Circular]]]]
+</p>
 [[Category:System exception classes]]